Vacheron Constantin

Hello all, just joined and I'm happy to be here.

I have just inherited this vintage VC from my father (which used to belong to my grandfather), so it has great sentimental value to me. I remember seeing this piece on my grandfather's wrist when I was a little kid. Thirty years have passed and now it's on my wrist. Nothing short of magical every time I look down at my wrist. I'm sure many of you can relate to the feeling. 

I don't have much information on this piece except it was purchased in Hong Kong during the late seventies or early eighties. It does not have a quick-set, and had glossy black alligator bands.

A couple of questions:

Is there a model number associated with this watch? And what's the correct method of setting the time and date? 

It tends to run fast by a couple of minutes after a few days and I'm nervous about moving the hands backwards. As there is no quick-set function, what's the best way of setting the date?

Much appreciated. 

-j